I think it will be Kimi. He's fast and now VERY confident and will probably be even MORE agressive. Plus... he is one of the few drivers of which traction controle was actually a hinderance to his driving style in how he would naturally enter a turn, and keep the car flat in the second phase and on exit.
Massa is good and fast IF he has empty track ahead of him or VERY slow drivers in front of him. If he has competition or competative cars in front... something happens to him and he loses his speed.